Cash back

I was at Superspar Mega Pinetown, bought few items and at the till, I requested for cash back and I was told that they don't do cash back with the bank I'm using, I asked since when because I always request for cash back at the same Spar, using the same bank card and I always get it, then the lady asked when was the last time I requested cash back with the same bank card, I told her it was on Thursday 17/06/2021 and I got it. She said the person who assisted me did me a favour, because they don't accept that bank card ever since.